Kristofer Engelhardt’s original “Beatles Undercover,” published in 1998, has been one of the most used books in our Beatles library. The original book cataloged everything you’d ever want to know about the Beatles’ outside musical activities.

Now Engelhardt has written a revised edition, out this month, called “Beatles Deeper Undercover” that updates the original. The new book is actually thinner than the old one (375 pages vs. 523 pages). The difference is the new volume has fewer pictures and a more streamlined layout. But the incredible detail of the original volume carries over into the new one. (See the slideshow at the bottom for pictures of Engelhardt and various celebrities involved in the book.)

We asked author Engelhardt how the new volume was compiled and here’s the full story:

“In 2007 I told my publisher that I had discovered enough new information and contributions by members of The Beatles to other artists’ recordings for a new book or volume two of ‘Beatles Undercover,’ and they agreed. As I began writing the book, I soon realized that in many cases there was no way to incorporate the new information without having it in the context of the information in the original book. Because of this and because the 550 page ‘Beatles Undercover’ had been out of print for many years, we decided to incorporate the original material.

“However, because there was about 35 percent new information, my publisher didn’t want to end up with an 800 page book. Therefore, it was decided that I would first see if I could edit down the original book by about half without editing out the critical information or data. This was no easy task. I edited out most of the background information in the biographies of each artist leaving just a snapshot of their careers and focusing in like a laser on the core story of their collaboration with a Beatle. By adopting a different layout, combining information, referencing to other portions of the book or outside sources, and omitting many photographs, I was able to edit the original book down to 200 pages but it required essentially re-writing most of the original book.

“This process took over a year. Then I began adding in the corrections, updates on each artist (chapter) and the new contributions and data. As with the first book, I was successful in contacting most of the new artists in the book for interviews. Due to the reputation of my first book and new technologies (web sites, emails, Skype etc), I was also able to contact many of the artists I wasn’t able to contact in the first book. This updating process took another full year.

“By the time I was finished we were up to 375 pages. There aren’t nearly as many photos in this edition, but like the first book, with a handful of exceptions, most of the photos in this book are new and have never been published before. What the reader is left with is a much more focused and user friendly book. 

“Many of the new collaborations were the result of Ringo Starr’s All-Starr Band. I interviewed most of the All-Starr Band members and while each brought a different perspective on the tours and working with Ringo, with one exception, they were unanimous in their praise, appreciation, admiration and respect for Ringo, which speaks volumes. The one exception was Dave Mason who, for the first time, gives his version of why he left the All-Starr Band. Billy Squier (and his constant re-writing of his story) and Eric Carmen’s musical frustrations give great insight into the inner workings of the All-Starr band. I found Jack Bruce’s experiences of finding that Ringo was still very much trapped by his fame sad. Richard Marx’s story about Ringo constantly telling him he was his favorite All-Starr Band member but not to tell the others, and then Ringo shouting this out to Richard later for everyone one in the band to hear, highly amusing. John Waite’s initial stage fright and Edgar Winter being reduce to tears (not in the book) after a taped show because his keyboards failed on “Frankenstein,” to be very personal moments. (Note from Steve: We especially loved Ian Hunter’s story, too.)

“I gained a much greater appreciation from Mortimer, Drew & Dy and Timon as to the frustrations of artists signed to Apple Records. Paul McCartney’s mentoring of the very young and impressionable Lindsay Pagano is nothing short of patronization at it best. Jonell Mosser’s telling of the origin of Ringo being in the New Maroons is recounted for the first time. I finally got the bottom of the Carlos Mendes and Jotta Herre story about ‘Penina.’ Jotta Herre was NOT a Dutch band but the Portuguese band McCartney jammed with at the Penina Hotel in Portugal and who likely recorded the song first.

“Tony Sheridan gave me a complete history and the story behind the recording of his and McCartney’s composition ‘Tell Me If You Can,’ which many people don’t know was officially released several years ago. I got a very detailed story from Hamish Stuart about the recording of his and Paul’s composition ‘Is It Raining In London?’ and why it hasn’t been released. I found Legs Larry Smith’s love and protectiveness of the late George Harrison to be very touching.

“TOTO’s Steve Lukather’s very colorful and heartfelt recollection of working with Paul and Linda, and George Harrison, and how George could fake all of The Beatles’ signatures are some of the best stories in the book. I was shocked, as was Eric Burdon, that he didn’t know Ringo drummed on his version of “Power To The People.” The Crickets’ story about trying to order vegetarian food with the McCartneys is precious. McCartney’s cousin, entertainer Ted Robbins, telling me about the public and the private Paul McCartney are most insightful as was his telling of Paul using an old showbiz trick he learned from Ted’s father that he has employed many times.

“The two most moving stories were that of Liam Lynch talking about working one-on-one with McCartney at LIPA during the time Linda was battling cancer and how it affected Paul; the other was Stan Perkins recounting an emotional moment with Harrison when he gave him his father Carl’s guitar shortly after his death, and Harrison talking to him about his and Carl’s battle with cancer. The greatest discovery was that of McCartney writing and recording two songs with a group in Barbados called Ivory. The two songs (”Freedom Land” and “Runaway”) were later re-recorded by Ivory, which were released in Barbados only.”

Engelhardt says that certain things in the first book were also missed or overlooked. “For example,” he wrote us, “For years no one documented that John Lennon joined in the encore playing tambourine on “The Bitch Is Back” during his appearance with Elton John at MSG in 1974. There are photos documenting this.”

If you loved the first book, you know what we’re talking about when we say this book is a core collection Beatle reference. We highly recommend it.

(Note: The author will be appearing at the Fest For Beatles Fans March 26-28 at the N.J. Crowne Plaza Meadowlands Hotel, Secaucus, N.J.